The FBI on Tuesday called on former Director William H. Webster to conduct an independent audit of the agency's actions before last month's Fort Hood, Texas, massacre, a sign that the bureau remains concerned it may have missed signs that could have helped prevent the shooting rampage that left 13 dead.

Mr. Webster, a former federal judge who served as head of the FBI from 1978 to 1987 and subsequently became CIA director, will also focus on whether FBI policies and practices should be changed as a result of the shooting.

"We must be sure that the systems we have in place give investigators the tools they need to carry out their responsibilities. At the same time, we must ensure constitutional protections and the confidence of the American public we serve," FBI Director Robert S. Mueller III said in a statement. "It is essential to determine whether there are improvements to our current practices or other authorities that could make us all safer in the future."

Maj. Nidal Malik Hasan, the suspect in the shootings, had been in e-mail contact with a radical imam, Anwar al-Awlaki, in the months before the shooting. Mr. al-Awlaki, who lives in Yemen, was in contact with Maj. Hasan as many as 20 times beginning in December 2008, according to the FBI.

An FBI-led Joint Terrorism Task Force knew about the contacts because it had Mr. al-Awlaki's communications under surveillance. The task force conducted a "preliminary assessment" of Maj. Hasan but didn't open a full-fledged investigation because it decided that the contacts were innocuous.

They said the contacts related to research that Maj. Hasan was doing in his job as a psychiatrist at Walter Reed Army Medical Center last year.

The Washington Times reported last month that two U.S. officials - an FBI agent and a military intelligence official - said that Maj. Hasan also had contact with other Muslim extremists, some of whom are under federal investigation and have links to al Qaeda.

The military official called the case "an intel debacle" and added "there is definitely a need for a fresh look."

The official also said that an Army officer such as Maj. Hasan communicating with Mr. al-Awlaki, a prominent figure in jihadist circles, should have raised serious suspicions. "It's one thing to know people in the Mafia," the official said. "It's something else again to be in regular correspondence with [mob boss] John Gotti."

Authorities say Maj. Hasan, 39, acted alone and is not part of any larger terror plot.

Maj. Hasan, who is reportedly paralyzed from gunshot wounds he received from two civilian police officers credited with stopping the massacre, faces charges in military court of 13 counts of premeditated murder. He could face the death penalty if convicted.

Mr. Mueller said Mr. Webster's review will be careful not to interfere with the ongoing criminal investigation, but will "have complete access and whatever resources necessary to complete the task."

When reached by The Times, Mr. Webster declined to comment on the appointment.

The decision to conduct an independent investigation comes after a preliminary review of the case that was conducted internally.

An FBI official who would only speak about the case on the condition of anonymity said the preliminary review largely confirmed what the bureau has previously disclosed about the case and that the new, external review aims to make use of Mr. Webster's law enforcement, legal and intelligence expertise.

"This decision was not driven by any finding in the preliminary review," the official said. "We see this as the next logical step in this review process."

The FBI on Tuesday called on former Director William H. Webster to conduct an independent audit of the agency's actions before last month's Fort Hood, Texas, massacre, a sign that the bureau remains concerned it may have missed signs that could have helped prevent the...